Electrolytic silver recovery from used photographic solutions is a common way to extend the life of such solutions.
An apparatus for the electrolytic recovery of silver from solutions containing silver is known from United States patent U.S. Pat. No. 5,378,340 (Van be Wynckel et al. assigned to Agfa-Gevaert NV) issued Jan. 3, 1995. The apparatus comprises an electrolytic cell including: a housing; an anode having an exposed anode portion within the housing; and a cathode having an exposed cathode portion located within the housing and encircling the anode. In use, silver from the silver-containing solution is deposited on the face of the cathode which is directed towards the anode. After the cell is operated for some time, the cathode is removed from the cell and replaced.
In a known method of removing silver from silver-containing aqueous liquids, the liquid to be treated is pumped into the electrolytic cell and electrical power is fed to the anode and the cathode to cause silver to be deposited on the cathode. The cathode is usually removable, and after a certain amount of silver has built up thereon, the cathode is removed and replaced. The build up of silver on the cathode surface during de-silvering has an effect upon the circulation of liquid within the cell, in particular the rate and uniformity of liquid refreshment at the cathode surface. This in turn has an effect upon the uniformity of the desilvering process.